This invention relates generally to the use of negative resistance line drop compensation in regulators employed to regulate output voltage levels of electric utility distribution substations. More specifically, this invention relates to control circuits for selectively and automatically introducing such compensation into substation regulator circuitry in order to reduce substation output voltage and, consequently, load current levels during periods of high customer energy demand or peak load conditions.
Distribution substation regulators having negative resistance line drop compensation circuitry have long been in use in the prior art. Basically, such prior art regulators allow an operator to manually adjust a resistance line drop compensator rheostat located on the regulator control panel such that the regulator control circuitry will perceive a higher substation output voltage than is actually present when a load current is flowing through the regulator, whereupon the regulator will lower the perceived output voltage to what the regulator perceives to be the proper range of output voltage levels. In reality, the regulator will then regulate the actual substation output voltage at and about a level which is below the regulated voltage level.
In the past such compensation has been used in the positive mode to keep substation output voltage level variations to an acceptable minimum at a specific geographic location in the distribution circuit. The compensation must be introduced manually into the regulator control circuitry in anticipation of such periods and removed or altered in anticipation of normal and peak substation loading. It is often difficult and time consuming for an operator to travel from his office to all of the regulated substations in a given utility system as frequently as may be required in order to make the desired compensator adjustments. While my invention utilizes such line drop compensation for an entirely different purpose, it provides for automatic introduction and removal thereof into and out of the regulator control circuitry and does not require repeated travel to and from the substation in anticipation of normally encountered load variations.
By means of my invention, this and other difficulties encountered using such compensation is substantially overcome. Moreover, my invention permits the use of negative resistance compensation in regulated substations to obtain a new and useful result not heretofore realized in the prior art.